Problem: Khan.scratchpad.disable(); Luis sells magazine subscriptions and earns $$4$ for every new subscriber he signs up. Luis also earns a $$26$ weekly bonus regardless of how many magazine subscriptions he sells. If Luis wants to earn at least $$52$ this week, what is the minimum number of subscriptions he needs to sell?
Explanation: To solve this, let's set up an expression to show how much money Luis will make. Amount earned this week $=$ $ $ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus Since Luis wants to make at least $$52$ this week, we can turn this into an inequality. Amount earned this week $\geq $52$ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus $\geq $52$ We are solving for the number of subscriptions sold, so let subscriptions sold be represented by the variable $x$ We can now plug in: $x \cdot $4 + $26 \geq $52$ $ x \cdot $4 \geq $52 - $26 $ $ x \cdot $4 \geq $26 $ $x \geq \dfrac{26}{4} \approx 6.50$ Since Luis cannot sell parts of subscriptions, we round $6.50$ up to $7$ Luis must sell at least 7 subscriptions this week.